1. Field of the Invention
Embodiments of the invention relate to a solar cell, a solar cell manufacturing device, and a method for manufacturing the solar cell.
2. Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in alternative energy sources for replacing the existing energy sources are increasing. Among the alternative energy sources, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes semiconductor parts, which respectively have different conductive types, for example, a p-type and an n-type and thus form a p-n junction, and electrodes respectively connected to the semiconductor parts of the different conductive types.
In some instances, an emitter region of a solar cell has a selective emitter structure including a lightly doped region having a relatively small depth of the p-n junction and a heavily doped region having a relatively large depth of the p-n junction, so as to improve photoelectric conversion efficiency of the solar cell.
Examples of a method for forming the selective emitter structure of the solar cell include a thermal diffusion method performed in a thermal diffusion furnace using a mask, a partial thermal diffusion method using a laser, and a method using an ion implantation device for implanting ion particles, which are accelerated at a high energy, into one surface of a silicon substrate.
In a related art method for forming the selective emitter structure using the ion implantation device, a mask is disposed between ions and the silicon substrate so as to implant ions only into a desired region of the silicon substrate, thereby selectively filtering the ions.